[Journal of the American Chemical Society, 2020] Three-dimensional Gold Nanosphere Hexamers Linked with Metal Bridges: Near-Field Focusing for Single Particle Surface Enhanced Raman Scattering (Sungjae Yoo, Jeongwon Kim, Jae-Myoung Kim, Jiwoong Son, Sungwoo Lee, Hajir Hilal, MohammadNavid Haddadnezhad, Jwa-Min Nam, and Sungho Park)